My cd/dvd burner won't work!

I’m looking for a usb cd/dvd burner for my dual core imac G5 as the built in decided to stop working with the error message saying something like ‘could not establish correct power level to calibrate laser for this media’???

Any suggestions as to what I could do or any ideas where I would find a goog external burner?

Thanks

What media is used when the message is given? It could be a crappy media problem and not a hardware problem. Suggest trying good media like Verbatim or Taiyo Yuden.